Shock absorber



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Patented Dec. 20v, `171927.

Jer-rn A. STEVENS, or LOWELL, MASSACHUSETTS, Asslonon rTo STEVENS PRODUCTS COMPANY, or LOWELL, MASSACHUSETTS, A CORPORATION' OE DELAWARE.`

SHOCK ABSOEBEE.

application sieanugust is. 1925. seria; Nafsaoea.

This invention relates to an improvement in shock absorbers for use in additionto and in conjunction with the usual bedyfspring 'of a vehicle or `adapted* to .be used onany appliance orjmecjhanism yhaving parts vInovab'le relative toeach other as a-psnubbing .or .dampening apparatus. The tendency 'fora-I1 automobile to swaygzoscillate,toeter andgj ack.- :rabbit .with an undulating movement when traveling at higher rates ofspeed is Well recognized and is due to theffact thateven the best macadam or concrete' roads contain .ripples that yaccentuate this undulatingftendency. This constant rising and 'falli-ng ,movement thatan occupant of a vehicle eX- periences occurs `With-out jar or jolt When etfective shock absorbers are used but is nevertheless annoying and oftentimes produces an illness similar to seasickness. While shock absorbers have toa great `degree `solved the problem of counteracting land neutralizing the shocks received'by'the vehicle so that zthe saine are transmitted tothe occupants thereof with a slight j ar and diminished forte-the inability of known Ashock absorbers lto ettectively damp the undulating te'ndencyrot the-springs and body oit the vehicle and return saine Vto the normal positionuof equilibrium is an outstanding defect.

Objects of this invention are to provide a shock absorber that Will readily neutralize the shocks received by the vehicle on which .said shook abeorberis mounted and quickly 4equilibrize the forces acting on kthe :springs and body of the vehicle; to kprovide ka shock absorber adapted to .elfectively absorb shocks and bring the :torces .acting` on theisprings and body of the vehicle into equilibrium yWithout affecting the resiliencyof the springs and ability of the device to neutralize shocks; to arrange a plunger electro-magnet in a shock absorbing device, snubber por `dampenei;

so that thenorinal position of ythe chassistof vthe vehicle relative tothe springs and Wheels under a normal' load lis eil'ectively `maintained by the action of said'electro-magnet; and to provide a device so ysimple in its construction that the same can ybe easily applied to an automobileor other vehicle Without changing its parts. l

Other objects-of the invention Will be apparent 'from the detailed description and appended claims hereinafter set forth. vFor rnerjeasing 17 of rubber.

purposes of illustration the invention is shown in the accompanying drawings, in ,Whichi [j ,Fig l is a vertical section ofthe shock absorbing device-showing the same connected Ito thje spring and bodyof a vehicle; and

Fig. Q is a side elevation-partly in section ot a plunge-r `electro-magnet snubber ,or y,dampener torni-ing a partei' the .shock abfisorber. y l l, l c

:is illustrated the numeral l designates y.the ,usual.semi-elliptic leaf spring mounted on the axle of a vehicle and adapted to support` the usual chassis or 4frame 2f In. ac-

efnfdincev with this in ventiona' shock absorbing` device. designatet ,as .a Whole .by y tue numeral 3, is inserted betweenone end of theleat spring 1 and the body or frame 2.

The shock absorber 3 comprisesv vra body `portion l adaptedto enclose a piston rodl 5 screw-threaded oneach end. AS sleeve 6 having; interior threads engaging the lower"` i threaded end. ofthe rod has on its exterior `surface ya shoulder 7 forming a seat for the coiled spring 9 surrounding the piston rod 5 and mounted between said shoulder and a rWasher 1l which is rigidly attached to the u.pper,.end ot the body portion 4- through the 'medium fof the screws 12.'.y A sleeve .6" kalso surrounds the piston ,rod 5 and rests on the upper end of the sleeve 6 providing a yseat .for asmallgcoiled spring` 10, hereafterk .re-

ferred to as a check spring, located between said sleeyef land,theavasher 11 and Within thejcoiled springt). Surroundingthe upper end of thefbody portion t and enclosing Athe Washer 111; is a spherical casing or cylinder .18 forming` a compression chamber 14. The

.lower iendot' the cylinder is rigidly attached ,to thegupper peripheral end of the body portion dthrough a series of screws 15f Enclosed within 4the cylinder 13 is4 yan outer casing' of fabric 1G containing an in- The casing 17 is adaptedk to be inilated through a valve 18 attached to they casing and extending through the top oit the cylinder, 13. The valve 18 may be the type of valve commonrlyernployed for inflating pneumatic casings.y The A.upper yend of the piston rod 5 extends through an opening ,ink the Washer 11 into the cylinder linemberf 13 and carries a piston 19 with a washer 20 located 'between the Y lower side of the casing 16 and as is obvious will further compress the air in the. compression chamber 14 on its upward movement. An eye member 20 is suitably mounted on the end of the `frame or body 2 of the vehicle and is pi-votally attached to a spindle 21 mounted on the inner end of an arm 22 extending from the body portion Il.

The arm 22 at its upper end carries a boltV 23 receiving the eye 24 of a projection 25 also mounted on the frame or bodyz 2 so that free movement is lpermitted between the rame'or bodyfof the rvehicle and the shock absorbing element.

An arm k26 is pivotally mounted 'inter-l mediate its end,`on the lower end of the sleeve 26. One end of the arm 6 is further 531 pivoted to a portion ot' the body 4: while said parts alone do not overcome the tend ency of the chassis or trame of the vehicle to assume an undulating movement. In fact the pneumatic cushion and auxiliary springs rather tend to increase the undulation of the vehicle and for that reasonthe plunger electro-magnet hereinafter described peculiarly cooperates with the shock absorber previously described to produce a structure in its entirety which has all ofthefbenelits of the pneumatic shock absorber and overcomes all ot its defects.

The electro-magnet 28 is'pivotally mounted on the arm 26 directly below the point where said arm is pivotally attached to the lower end oi the sleeve 6. The electro-magnet comprises a body portion 29 containing a solenoid 3() insulated Jfrom and in surrounding` relation to a plunger 31 which is nnignetized` by the electric current passing through said solenoid. The plunger 251 has an upper reduced threaded portion 82 which is formed with a concave seat 33 at its outer end to receive a. spherical end portion 341 of the'pin which is pivotally attached at its opposite end to the arm 2G. The pin 35 special generator or battery provided for the purpose. i

The operation of the device is as follows: When a shock is transmitted to the spring 1 the force of said shock is not directly carried to the rame2 but causes the piston 19 to rise upwardly against the pressure' of the compressed air in the compression chamber 14 so that the 'shock is` counteracted and neutralized and very slightly conveyed to the occupants oi the vehicle as is well known and understood. A check spring is also used for asuperimposed load when the devices are used on or-within any structures-that is, it is used for a check spring and for'providing additional spring carrying capacity to take care of extra loading of the structures' to which the device is attached. kThe check springs thus perform the double function of a check spring to absorb eXtreme shocks and a resistance for extra loading of any. automobile, vehicle or structure on whichthe devices'are used. The electro-magnet 29 not only serves to impede and soften the shock transmitted to the frame' 2, but whenthe forces acting on the vehicle are such as to tend to cause the piston 19 to continually oscillate in the cylinder 13 and thus give an undulating movement to the frame 2 that tendency will be quickly overcome by reason of the electrosmagnet acting as a drag on the'moveinent of the piston and thus causing a balancing of the forces acting on the piston and establishing complete equilibrium.

Theplunger electrofinagnet as shown in Fig. 1 is normally positioned with respect to the normal relative position of the springsV and chassis so that said plunger exerts its maximum retarding force. in this position. The plunger electro-magnet when displaced from its normal position, shown in Fig. 1, by the functioning of the shock absorbing device in' neutralizing shocks, constantly drags on said device and tends to assume its normal position with the result that any undulating movement of springs and chassis is quickly damped by the action oi' said electro1nagnet.

The Yinitial reaction of the piston of the shock absorbing element to a shock results in a relative long stroke ot said piston and `consequently of the electro-magnet plunger rlhe longer and which is attached thereto. slower strokes of the piston and movable elements of lthe shock absorbing device are immediately followed by shorter and faster strokes until the elements are rapidly oscillating. This is the normal reaction of the shock absorbing device to a single shock provided no other for-ces are acting on said device. It frequently happens, however, that after the torce ot' a severe shock has set the movable elements ot the device in motion the ripples on the surface of the roadway lili) lil() will furnish .uuiiicient impetus to the movable elements oi the shock absorber to sustain them in their initialr movements with theresult that the body of the vehicle asplunger is intensified.

The 'lunrer electro-mavnct is arranved' b D b and adjusted with respect to the relative Yposition of; the springs and chassis under normalload soasto exercise its maximum vretardiiig effect injtli-at position.

, lVhile the plunger electro-magnet, 'snubber or dampener is .shown and described as inconnection with `a vehicle, it is notlimy ite'd thereto but may beembodied in any de'- vice, having parts movable relative to each other to dampen and retard the movement of said parts.

claim:

l. A shock absorber, adapted to be mountedon theusual trame and'springs of a vehicle, comprising a compression chamber contain ing compressediairriiiounted'onl the frame of said vehicle, a piston `carried bythe springs 4ofsaid vehicle adapted to oscillate in said chamber, additional meansl adapted to retard the movement .of said piston andfuither means acting as a drag on said piston. quickly to arrest the relative movement of said piston and chamber. f

2. `A shock absorber, yadapted to bel mounted .on the usual frame and springs of a vehicle, comprising a compression lkchamber containing compressed air, a piston adapted 4to oscillate in. said chamber, additional means adapted .to retard the movement of said piston and further Vmeans acting asla `drag on said piston quickly to arrestcthe relative movement `of said piston andl chamber. y

3. A shock absorber, adapted to be mounted, on the usual traine and springs ot a ve- -liicl,e, comprising a compression kchamber containing compressed air, a piston adaptedv tor oscillate in `said chamber, mechanical means adapted to retard the movement of said piston and a. solenoid acting as a drag on said piston quicklyy to arrest the relative movement oi said piston and chamber.

-l. A shock absorber, adapted to be mount! ed on the usual frame and springs ci a vehicle, comprising a r`compression chamber containing compressed yair mounted on the 'lrameot said vehicle, a pistoncarried by the springs .ot said vehicle ada )ted to ofifcillate in said chamber, means on tlie piston adaptmeans attached toy said piston and adapted to `act as a drag quickly to arrest the relative movement of said piston and chamber. 5. A shock absorber, adapted to be mounted on the usual frame andsprings or' a vehicle,*coniprising va compression chamber containing rcompressed air mounted on the frame ot said vehicle, apistonfhaving apiston rod carried bythe springs of said vehicleand adapted to oscillate in said chamber, a coil spring surrounding the piston rod and adapted to be compressed on the'upward movement of the piston,"and means acting als a vdrag on said piston quickly lto arrest'the relative movement of said piston and chamber. v c

6. Ashock absorber for vehiclescomprising a casing having a chamber therein, 'a

closed collapsible inner casing illed with a conipressible fluidy undery pressure Within said chamber, a piston having a piston rod arranged to compress said inner casing, a relatively' large coil spring surrounding the ypiston rod and adapted, to'be compressed on .the upward movement of the piston, a relatively small coil spring surrounding the piston rod and contained Within the large coily spring, and means racting as ai dragon said piston vquickly to arrest the relative {movement of said piston and chamber. J

7 .1A shock absorber, adapted to 'be mounted on a vehicle,"comprising at Aleast two separate and distinct means for neutralizing and counteracting the shock received by said vehicle and an electro-magnet so arranged asquickl'y to arrest the forces set in wey motionb'y vsaid shock to bring them into a c state/ot equilibrium. l c c 8. A shock absorber, adaptedr to be mounted on a vehicle, compris-ing a compression chamber, a piston radapted'to oscillate in said chamber, compressible members attached 'tosaid` pist-on apart from the compression ychamber and an electro-magneten rangedto act asa drag on said piston quickly to arrest the,relativemovement of said piston andchamber. Y

` i9.' A shockabsorber for vehicles comprising a compression chamber containing coniypressed airvmounted on Athe body of said vehicle, a piston adapted to oscillate in said chamber mounted on the springs of 'said vehicle and a plunger electro-magnet mally positioned Withiespect to the normal relative position ot the body and springs so that said plunger acts vas a maximum drag on said piston when `in its normal position and being displaced tliereironi positivelyy tends to recover the normal position of body springs and plunger.

l0. A shock absorber. adapted to be mounted on theiisual chassis and springs ot' a vehicle,'coinprising at least tivo separate and distinct means responsive to the `relative no rmovement between the chassis and springs forneutralizing and counteracting a shock received by said vehicle and additional means normally positioned with respect to the normal relative position of the body and springs adapted to return said body vand springs to normal position after being displaced therei'rom.

l1.u A shock absorber adapted to be mounted on the usual chassis and springs of a vehicle comprisingmeans responsive to the relative movementbetween the chassis and springs for neutralizing and counteracting a shock received by said vehicle and means positioned with respect to the normal relative position of the body and springs under normal load to exercise a maximum retarding eliect on relative movement of the chassis and springs in that position.

12. A shock absorber, adapted to be mounted on a` vehicle, comprising at least two separate and distinct means for neutralizing Vand counteractine the shoclr received by said vehicle and an electro-magnet snubber adapted, by opposed electric currents in action through a solenoid, quickly to arrest the forces set in motion by said shock to bring them into a state of equilibrium.

shock absorber, adapted .to be mountedon the usual chassis and springs of a vehicle,wcomprising means responsive to the relative movement between the chassis and springs for neutralizing and counteracting a shook received by said vehicle and means, providing electrical forces opposingthek relative movement of the ,chassis and springs, positioned with respect to the normal relative position of the body and springs under normal load to exercise. a maximum retarding effect on relative movement ot the chassis and springs in that position.

14. In a device of the character described comprising a member adapted to be set in motion in response to a shock and move relative to another member connected therewith, means providing electrical forces acting against the movement of said members to retard or stop relative movement therebetween, the dampening effect of the electrical forces tending to retard and stop relative movement of said members being greatest in the normal position ot said members.

l5. il snubbcr or dampener of the class described adapte-d to be positioned with respei-t to the normal position ot two members movable relative to each other and providing electrical yielding means retarding the said relative movement ot the members and adapted to exercise a maxlmum retarding eti'ect on said members when in normal position.

16. A snubbcr or dampener of the class described adapted to be positioned with re,- spect to the normal position of relatively movable members and providing electricalV forces which are greatest in the normal position acting in opposition to the movement of said members and adapted to bring them into a state ot equilibrium. i

17. A device for taking up shock 'caused by sudden relative movements of two members, comprising a casing having a chamber therein, a closed collapsible inner casing illed with a compressible fluid under pressure within the cha1nbersa`id inner casing being fixed to one of said members, a iston having piston rod carried by the ot er of said members and adapted to oscillate in said chamber, a coil spring surrounding said piston rod and adapted to be compressed on the movement or' said piston in one direction and meansacting as a drag on said piston quickly to arrest the relative movement of said members. A 1S. A device for taking up shock caused by sudden relative movements oftwo members comprising a casing having a chamber th'e'ein, a closed collapsible rubber casing 'within said chamber. having a compressible 'fluid under pressure therein, said rubber being connected to one of said members, a piston having a piston'rod carried by the other of said members and. adapted to oscillate in said chamber, a relatively large coil spring surrounding thepiston `rod and adapted to be compressed on the movement ot' the pfston in` one direction, a relativelv small coil spring surrounding the piston rod and contained within the-large coil spring, and means acting as a drag on said piston quickly to arrest the relative movements of said members.

l19. Ashocl absorbing device for cushioning the shock caused by a quick relative movement of two members, comprising a casing fixed to one of said members having al cliambered portion therein, a flexible diaphragm separating the chambered portion from the remainder of the casing, the chambered portion being filled with a compressible liuid, a rocker arm journaled near one oi its ends to said casing, the other of said members being connected to said rocker arm so as to rockit on a relative movement ot said members, a piston pivo'ted to said rocker arm having a head bearing against said diaphragm, an abutment fixed to said casing, a spring surrounding` said piston and bearing at one endagainst said abutment and at the other end against'an abutment on said piston and asecond spring acting-in parallel with the first mentioned spring Vto absorb only extremely heavy shocks and to assist in bearing only an extremely heavy load.

20. ln a shock absorber, a casing, a lever pivoted thereto, an air cushion in said casing, a piston pivoted to said lever,itwo springs adapted to be compressed in parallel by said piston on movement of said lever, said piston also bearing against said air cushion, the springs beingso arranged that one is compressed to a predetermined degree before the other is brought into aotion.

21. In a Shook absorben@ easing, :L lever pivoted thereto, an air cushion in `said oasing, a` piston pvoted to said lever, two concentric springs surrounding the piston rod and bearing against `abutments thereon, the springs adapted to Work in parallel and arranged so that onefis brought into action before the other, said piston also acting against seid air cushion.

22. Inn shook absorber, a casing, u lever pivoted thereto, an zur cushion in saideasing, a piston pivoted to said lever, two concentric springs surrounding the piston .rod und bearing against abutments thereon,"the

springs adeptedto Work in parallel and arranged so that one is Compressed by a relatively slight shock but both are compressed by a relatively heavy shock, said piston also bearing against Said air cushion.

Signed by me at Lowell, Massachusetts, this 12 day of August, 1925.

' JOHN A. STEVENS. 

